Dead HP 35

[krazyk]

I have inspected both sides of the main keyboard pcb and measured the resistance between the battery terminals and the + and - entry points and the resistance was very low and the continuity beeper went off on the power connections from the battery terminals al the way to the main pcb.

It is a good point though re internal copper going BLACK as I see that a LOT with my retro computer collection. It will not hurt replacing the link wires just to see if it reduces the voltage drop of particularly Vcc. I need to get it to 8.2V.

I have cleaned the power switch already so I dont think thats an issue now

   

I DO own a laboratory power supply and can use IT to supply 3.9 volts at 500mA max just to eliminate those AAA 3 pack batteries from the equation. I am waiting for a delivery of some Enerloop NiMH batteries as thats what I am using in my HP25 and 33C and they work very well.

I have been using 3 semi depleted AAA alkaline batteries that are showing around 1.3V each DC but I am aware that their current delivery capability can also be DEPLETED too. If I find out its THAT I will be very annoyed with myself.

Will update with more info soon.

Kris